I havent seen anything on this yet and i was wondering if anyone had.

When exploring, will going from province to province be seemless? Or will we have to fast travel to go from province to province?

This is important to me, as i love exploring so much.

Theres loading screens, fast-travel happen between shrines and in Cyrodil between keeps. Theres exploration too, but we dont know exactly how big zones are yet, compass show you POIs (point of interest) when you travel around the zone.

Waypoints will be used to allow fast travel once they have been found I believe. Not sure what they will be called... gates, portals, etc... But not a taxi type thing. The ones in RIFT are pretty cool, hopefully like them.

It is also been said that they will be in Cyrodiil and you will be able to take them from enemy factions to disrupt their travel in the PvP zone. THAT sounds cool!

Hopefully, and very likely, it will be seamless. As in, a gentle fade of art styles from province to province.

If you roll your main in Ebonheart, as an example, then you will need to roll alts in the other two factions as well or you will only see 1/3 of the games PvE content. As it stands now you won't be able to travel to opposing faction provinces or even talk to them when you meet on the battlefield in Cyrodiil. There are posted topics about this already and I would suggest reading those topics.